1. Field of the Invention
The present invention relates to a display structure, a method of manufacturing a display structure, and an electronic apparatus.
2. Description of Related Art
Recently, in portable electronic apparatus such as a mobile telephone, an electronic personal organizer, and a PDA (personal digital assistant), a flat panel display has been widely used as a display device showing a variety of information. A liquid crystal display (LCD), an electro luminescence panel (ELP), a plasma display panel (PDP), and the like are cited as the flat panel display.
In the portable electronic apparatus, the miniaturization of overall apparatus is required. In addition, there is a demand that an area referred to as “frame” hereafter) other than a display area in the display device (display) be narrowed because of a demand for good design. That is, there is a demand that the display area be made as large as possible and the frame be made as narrow as possible because of a demand that the display is housed within limited space in a housing, and an amount of information which can be shown be increased. Technique for mounting an electronic circuit and an IC for driving on a back side of a substrate has been considered with the aim of such narrowing of the frame of the display, as is shown, for example, in Japanese Unexamined Patent Application, First Publication No. H05-323354.
Here, there is a COG (chip on glass) mounting or a COF (chip on film) mounting as a method of mounting a display. The COG mounting is generally a method of mounting an IC chip for driving on a glass substrate. The COF mounting is generally a method of connecting a film (flexible) substrate such as a polyimide film to the glass substrate so as to mount the IC chip for driving on a film substrate.
However, it is difficult to make the frame narrow in the conventional COG mounting. The reason is that, in the conventional COG mounting, the IC chip for driving is mounted on the frame of the display such that an area, to which the display area, an IC chip area, and a flexible printed circuit (referred to as “FPC” hereafter) are connected, is required in one side of the display. Here, an area to which the FPC is connected is one to which the FPC connecting to external of the portable electronic equipment is connected.
On the other hand, in the COF mounting, to make the frame narrow is possible by folding the film substrate so as to dispose the IC chip area on the back side of the display area of the display. However, a coefficient of thermal expansion of the film substrate is greatly different from that of an IC chip such as a silicon chip installed on the substrate. Consequently, in the COF mounting, there is a problem that alignment and mounting condition in IC chip mounting fluctuate with temperature changes such that a product life is apt to become short.
The present invention takes such conditions into consideration, with an object of providing a display structure of which the frame can be narrowed, and preventing it from temperature changes so as to be capable of prolonging its product life, a method of manufacture thereof, and electronic apparatus therewith.